Subject(s)
Phenothiazines/analysis , Indicators and Reagents , Solutions/analysis , Tablets/analysisABSTRACT
Simple colorimetric methods are reported for determining both acetaminophen and oxyphenbutazone. These methods are based on coupling between the phenolic compound and the diazonium salts of both sulfanilic acid and p-nitroaniline; the optimum conditions for the reactions were carefully studied. For acetaminophen, the reaction products with diazosulfanilic acid and diazo-p-nitroaniline show maximum absorbance at 480 and 425 nm, respectively. The mean percentage recoveries for authentic samples were 99.5 +/- 1.1 and 100.6 +/- 0.66, respectively (P = 0.05). For oxyphenbutazone, the obtained colors showed maxima at 385 nm with diazosulfanilic acid and 490 nm with diazo-p-nitroaniline reactions. The mean percentage recoveries for authentic samples were 99.8 +/- 0.27 and 100.1 +/- 0.57, respectively (P = 0.05). The proposed methods were successfully applied to the analysis of commercial preparations; results were statistically compared with those of other methods.
Subject(s)
Pharmaceutical Preparations/analysis , Phenols/analysis , Acetaminophen/analysis , Colorimetry/methods , Dosage Forms , Indicators and Reagents , Oxyphenbutazone/analysisABSTRACT
A spectrophotometric determination of piperazine and some of its salts is described. The method depends on the UV measurement of the N-nitroso derivatives formed by the interaction of piperazine with nitrous acid. The chromophore is developed by heating the reaction mixture at 80 degrees C for 15 min, at pH 2.3--2.6. Beer's law is obeyed in the range 1--15 micrograms/mL.
